1. Field of the Invention
This invention is related to coating compositions and more specifically to a spray on formula for reducing the glare and relection characteristics of the typical cathode ray tube (CRT) screen which only minimally effects the light intensity and clarity of the image viewed therethrough.
2. Prior Art
The need has arisen for a coating composition for a CRT tube which has anti-reflective properties but which does not simultaneously reduce the clarity or light intensity passing through the screen beyond an acceptable level and which also allows "leaking" or dispersion of accumulated excess electrostatic energy therethrough. Those who work in front of cathode ray tube screens common to most of today's personal computers, as well as television screens, are acutely aware of the effect on viewing brought about by reflection of ambient light and by glare emanating from within the CRT itself. The glare and reflection visited upon the viewer is a result of the reflective nature of the glass CRT screen.
It is common for the CRT user simply to turn down the intensity level of the display to reduce glare, which unfortunately has an adverse effect on the visibility of the characters with a consequent increase in reading effort. This increased reading effort has been shown to lead to eye strain, headaches and fatigue. In the past, efforts have been directed to reduce the glare and reflection by placing anti-reflective films over the screen which are expensive to manufacture and ship and are especially cumbersome to apply, e.g., by cementing with adhesives or by heat sealing or press welding. Of particular interest is U.S. Pat. No. 3,356,523 to Libbert which discloses a polystyrene film containing an anti-reflection coating.
Further attempts at reducing the glare and reflection above mentioned are embodied in mechanical screens or filters as an attachment to the CRT as disclosed in U.S. Pat. No. 4,427,264 to Kamerling and in U.S. Pat. No. 4,577,928 to Brown. Inherent in mechanical screen apparatus is the limited viewing angle allowed as a result of the physical dimensions of the add on screen.
Also of nominal interest are the following U.S Patents:
______________________________________ Niwa 3,698,761 Binghan 3,527,729 Horvath 4,413,084 Blake, Jr. 4,507,426 Barsotti 4,614,683 ______________________________________
It has not heretofore been proposed to provide a spray on single layer anti-reflection coating for the surface of a CRT screen which difuses ambient light and allows accumulated excess electrostatic energy to be dissipated therethrough while causing no more than 5% loss in light intensity and clarity.